Head extent of VMFS. The head extent identifies the VMFS. However,
the head extent should not be used to identify the VMFS across host
reboots. The actual identifier is specified in "vmhbaI:T:L" format
which is not guaranteed to be stable across reboots. Define a volume
name that is unique to the host and use it to refer to the VMFS.
Alternatively, the immutable UUID of the VMFS can be used after it
is created.

majorVersion

xsd:int

Major version number of VMFS. This can be changed if the VMFS is
upgraded, but this is an irreversible change.